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S Clergeau-Guerithault

Publications and source records attributed to S Clergeau-Guerithault.

At least 19 recordsLinked to original sources
PubMed1991

[The expression of various cytokeratins by epithelial cells of calcified odontogenic cysts].

The calcifying odontogenic cyst (COC) is a rare lesion without specific clinical characteristics. Its diagnosis is essentially histopathological showing the presence of ghost cells associated with narrow squamous epithelium, the basal strata of which consist of clearly delineated cells differentiating in areas of the stellate reticulum in a similar way to ameloblastoma. The results of ultrastructural observations of the ghost cells as well as histochemical and immunohistochemical studies suggest that they are the sites of abnormal keratinisation. The aim of this study of one COC mas to locate the stages in epithelial maturation associated with the formation of ghost cells. Six monoclonal antibodies were used; three with a wide spectrum (KL1, AE3, AE1), two with a narrow spectrum against high molecular weight cytokeratins (AE2, AE8) and one against vimentin (M725). Histopathological examination of the COC revealed three different types of cells in the epithelial lining and the epithelial islands; small basal cubic cells surrounding larger ones placed centrally or suprabasally; balloon shaped cells or flattened ghost cells rolled up on themselves to resemble keratinising pearls, or cornifying cells. The ghost cells and cornifying cells had an altered distribution of their cytokeratins demonstrated by the absence of staining of antibodies against cytokeratins. The differentiated cells adjacent to them showed cytokeratins typical of squamous epithelium rather than those associated with the process of keratinization. The coexistence of cornifying and ghost cells testifies to the great potential of odontogenic epithelium to form numerous epithelial islands.

Adult↗
PubMed1991

A scanning electron microscopic study of the enamel of neonatal teeth.

Neonatal teeth, two mandibulars incisors and one maxillary central incisor, from two separate patients were examined, by SEM. Besides typical enamel anomalies, the incisors exhibited partial or total absence of root formation. These findings suggest that the early eruption of natal and neonatal teeth is dependent on osteoblastic activity within the area of the tooth germ. The reported cases show that teeth may erupt without root formation and without periodontal ligament which correlate with the role of the dental follicle during tooth eruption.

Dental Enamel↗
PubMed1990

[Expression of certain cytokeratins in the epithelium of dentigerous and primordial cysts].

The histopathologic diagnosis of odontogenic cysts is based mainly on the morphological nature of the epithelial lining of the cyst. A standard immunocytochemical method based on anticytokeratin monoclonal antibodies was used for the diagnosis of dentigerous and primordial cysts: 12 odontogenic cysts were diagnosed on clinical, radiological and pathological criteria in 9 dentigerous cysts and 3 primordial cysts. The anticytokeratin antibodies used in this study were KL1 (Immunotech, France) and AE1, AE2, AE3 and AE8 (ICN-Miles, France). The anticytokeratin antibodies used stained only the epithelial cells confirming their accuracy. The KL1 antibodies stained homogeneously the various epithelial cells. This positive reaction was not modified by the various fixation methods used. Some reactions observed with AE antibodies seemed to be modified by Bouin's fixative. The staining homogeneity of the primordial cysts and the staining heterogeneity of the dentigerous cysts seemed to be related to morphological aspects of their respective epithelia. The epithelial reactions in these 2 types of cysts towards inflammation were different.

Antibodies, Monoclonal↗
PubMed1989

[Histopathology of odontogenic cysts].

Odontogenic cysts present problems of diagnosis, radiology and histopathology. This review of the literature considers the current system of classification and reveals a level of agreement with regard to the major categories of cysts. The term "developmental odontogenic cyst" embraces primordial cysts (or odontogenic keratocysts), gingival cysts (newborn and adult), lateral periodontal cysts, eruption and dentigerous cysts and odontogenic calcified cysts (Gorlin cysts). "Inflammatory odontogenic cyst" includes: the radicular cysts and its etiological variance, residual cysts, inflammatory collateral cysts, periodontal cysts and inflammatory follicular cysts. Clinical symptoms are not in themselves sufficient to differentiate between several of the different categories. A combination of clinical and histopathological evidence is essential if a definitive diagnosis is to be achieved and the risk of carcinoma eliminated. Developmental or inflammatory cysts arise from cells involved in the development of the dental organ.

Dentigerous Cyst↗
PubMed1985

Dentinogenesis imperfecta type III with enamel and cementum defects.

Ground sections and scanning electron microscopic studies of primary teeth from a 2-year-old child whose teeth showed absence of enamel and large pulp chambers are examined. The findings suggest a diagnosis of odontodysplasia in a case classified as dentinogenesis imperfecta type III.

Child, Preschool↗
PubMed1984

A scanning electron microscopic study of dentin dysplasia type II in primary dentition.

Dentin dysplasia type II is a rare autosomal dominant defect which affects dentin formation in both the deciduous and the permanent dentitions. The scanning electron microscopic study performed on a primary central incisor presents some findings similar to those reported in dentinogenesis imperfecta. Because of the lack of published reports on dentin dysplasia type II, it is difficult to ascertain definitive characteristics of this dentin abnormality.

Child, Preschool↗
PubMed1975

[Electron microscope study of bacteria in dental plaques following the application of fluorides (author's transl)].

Gels containing fluorides can have profound effects on dental plaques. These gels contain 2% fluorides in the form of sodium monofluorophosphate and sodium fluoride and are buffered to pH 6.5 when applied to teeth they: - encourage the disappearance of certain bacteria, - inhibit the division of cells and diminish their storage of glycogen, - cause a thickening of the bacterial cell wall, - lead to modifications of the bacterial cell membrane, - precipitate the degeneration of most forms of bacteria, - cause the rapid mineralisation of many bacteria. These widespread effects, and the wholesale degeneration of microbial forms, are a reflection of a major breakdown in bacterial metabolism, and provide a partial explanation for the role of fluorides in the prevention of dental caries, and are in accord with previous biochemical and microbial observations.

Adolescent↗
PubMedDate not supplied

[Ultrastructural study of bacterial plaques from caries-free human subjects (author's transl)].

Bacterial plaques from the teeth of individuals without caries were prepared for examination under the electron microscope (Ryter and Kellenberger's fixation). Microbial polymorphism within bacterial plaques has previously been usually studied in relation to the age of the plaque. Actually, the presence of polymorphous micro-organisms and variations in microbial density observed in 48 hours old plaques, must be related to other factors. Micro-organisms of the same type, as well as bacteria of different types which adhere together, reveal symbiosis and a competition process within the bacterial plaque, thus leading to changes in metabolism and lysis of many of the bacteria. Disturbances in bacterial cell walls; septal vesicular formation and intracellular structures are observed. Bacteriophages found in the plaques may be the cause of lysis of bacteria. Disturbances in bacterial metabolism could explain the lack of carcinogenicity of micro-organisms, and bacterial antigenic complexes which induce probably useful immunological reactions in the host are revealed by the lack of dental caries.

Adolescent↗